Work machine and components thereof

1. A work machine controller comprising: a detection unit configured to detect a behavior and a current position of a work machine that achieves a predetermined operation while moving a target area; a service path defining unit configured to define a contour service path and a plurality of straight service paths, the contour service path running along the periphery of the target area, the straight service paths being defined by dividing the target area enclosed by the contour service path into two or more blocks with straight lines; a turning behavior defining unit configured to determine intersections between the contour service path and a pair of straight service paths, the pair of straight service paths being adjacent two of the straight service paths, the work machine being designed to travel along one of the pair of straight service paths in a first direction and travel along the other of the pair of straight service paths in a second direction that is opposite to the first direction, the turning behavior defining unit defining a turning behavior including backward movement of the work machine along a path connecting the adjacent intersections; and a control unit configured to produce a travel control signal to control a travel drive mechanism included in the work machine by using the travel control signal, the travel control signal being used to move the work machine along the contour service path and the straight service paths defined by the service path defining unit on anywhere other than the intersections between the contour service path and the straight service paths, based on the behavior and current position of the work machine traveling in the target area and information about their changes, and to turn the work machine in accordance with the turning behavior defined by the turning behavior defining unit when the work machine reaches one of the intersections, wherein the turning behavior defining unit is adapted to define at least one of first, second, and third turning behaviors, based on geographical features and attribute information including the body size of the work machine, a work width, and a shape of a curved line path followed by the work machine when it turns, the first turning behavior being for allowing the work machine to turn from one straight service path to another straight service path in such a manner that the work machine travels along a first straight service path that is one of the pair of straight service paths, passes through an intersection between the first straight service path and the contour service path, moves and turns ahead toward an extended line from a second straight service path which is another straight service path, moves straight back from an intersection with the extended line from the second straight service path until the work machine reaches an extended line from the first straight service path, and then moves and turns ahead toward an intersection between the second straight service path and the contour service path; the second turning behavior being for allowing the work machine to turn from one straight service path to another straight service path in such a manner that the work machine travels along the first straight service path, passes through the intersection between the first straight service path and the contour service path, moves ahead by a predetermined distance on the extended line from the first straight service path, moves and turns back toward the extended line from the second straight service path, moves straight ahead from the intersection with the extended line from the second straight service path until the work machine reaches the extended line from the first straight service path, and then turns back toward the extended line from the second straight service path; and the third turning behavior being for allowing the work machine to turn from one straight service path to another straight service path in such a manner that the work machine travels the first straight service path, passes through the intersection between the first straight service path and the contour service path, moves and turns ahead in the direction opposite to the second straight service path, stops temporarily, moves straight back to the intersection with the extended line from the first straight service path, and turns back toward the extended line from the second straight service path.

2. The work machine controller as claimed in claim 1 , wherein a curved line path followed by the work machine when it turns is an arc of one quarter of a circle having a minimum turning radius with which the work machine can turn.

3. The work machine controller as claimed in claim 1 , wherein the service path defining unit defines a bridge line path to a destination point by defining, in addition to the contour service path and the straight service paths, a circle whose center is at a current stay position of the work machine and whose radius is equal to n (n is a natural number) times the length from the current stay position to a check position after the work machine has traveled a predetermined distance, selecting a position on the periphery of the circle that is closest to the destination point, the position corresponding to an intersection between the periphery of the circle and a line segment connecting the current stay position to the check position, redefining the circle with this position used as a new stay position, and repeating these operations until the new stay position gets close to the destination point.

4. The work machine controller as claimed in claim 3 , wherein the destination point is at a position where the work machine is away from one of the straight service paths in the direction outward of the target area by an amount that is equal to the minimum turning radius with which the work machine can turn, the destination point being at a position at which the work machine can begin the operation.

5. The work machine controller as claimed in claim 4 , wherein the service path defining unit is configured to define a bridge line path by determining a first position (C 1 ) on an extended line from a straight service path (L 17 ), from a work end position (R 14 ) on the straight service path (L 17 ), the first position (C 1 ) being away from the work end position by an amount equal to a straight service path departure margin, determining a second position (C 2 ) on an extended line (L 27 ) extending outward from the contour service path with a slope of a straight line connecting the work start position (S 1 ) on the contour service path and a subsequent work position (S 2 ) on the contour service path, the second position (C 2 ) being away from the work start position (S 1 ) by a distance equal to a cutter blade lowering margin, and determining a fourth position (D 3 ), a fifth position (D 1 ) and a sixth position (D 2 ), the fourth position (D 3 ) being away from a third position (C 3 ) by a distance equal to a contour service path entry margin on the normal line that is perpendicular to the line connecting the first position (C 1 ) and the second position (C 2 ), the third position (C 3 ) being the midpoint of a line segment connecting the first position (C 1 ) and the second position (C 2 ), the fifth position (D 1 ) being at an intersection between the extended line from the straight service path (L 17 ) and a straight line that passes through the fourth position (D 3 ) and is parallel to a line segment connecting the first position (C 1 ) and the second position (C 2 ), the sixth position (D 2 ) being at an intersection between the extended line (L 27 ) and the straight line that passes through the fourth position (D 3 ) and is parallel to the line segment connecting the first position (C 1 ) and the second position (C 2 ), the bridge line path being a path through which the work machine that has passed through the work end position (R 14 ) via the straight service path (L 17 ) travels to the work start position (S 1 ) on the contour service path after passing through the fifth position (D 1 ), the fourth position (D 3 ), and the sixth position (D 2 ) in this order.

6. The work machine controller as claimed in claim 3 , wherein the control unit records the contour service path, the straight service paths, and the bridge line path in a predetermined memory with these paths being associated with a map of the target area, and produces the travel control signal according to the current position and the information recorded in and read from the memory at the beginning of the operation in the target area.

7. The work machine controller as claimed in claim 1 , wherein the control unit produces a work control signal and controls a work drive mechanism included in the work machine by using the work control signal, the work control signal being for use in quitting, by an amount equal to a predetermined margin size, the operation before beginning and completion of the turning behavior defined by the turning behavior defining unit.

8. A work machine that achieves a predetermined operation while moving a target area comprising a controller, the controller having: a detection unit configured to detect a behavior and a current position of the work machine; a service path defining unit configured to define a contour service path and a plurality of straight service paths, the contour service path running along the periphery of the target area, the straight service paths being defined by dividing the target area enclosed by the contour service path into two or more blocks with straight lines; a turning behavior defining unit configured to determine intersections between the contour service path and a pair of straight service paths, the pair of straight service paths being adjacent two of the straight service paths, the work machine being designed to travel along one of the pair of straight service paths in a first direction and travel along the other of the pair of straight service paths in a second direction that is opposite to the first direction, the turning behavior defining unit defining a turning behavior including backward movement of the work machine along a path connecting the adjacent intersections; and a control unit configured to produce a travel control signal for traveling along the contour service path and the straight service paths defined by the service path defining unit on anywhere other than the intersections between the contour service path and the straight service paths, based on the behavior and current position detected by the detection unit and information about their changes, and turning in accordance with the turning behavior defined by the turning behavior defining unit when the work machine reaches one of the intersections; the work machine further comprising a drive mechanism that is adapted to drive itself in response to the travel control signal produced from the controller, wherein the turning behavior defining unit is adapted to define at least one of first, second, and third turning behaviors, based on geographical features and attribute information including the body size of the work machine, a work width, and a shape of a curved line path followed by the work machine when it turns, the first turning behavior being for allowing the work machine to turn from one straight service path to another straight service path in such a manner that the work machine travels along a first straight service path that is one of the pair of straight service paths, passes through an intersection between the first straight service path and the contour service path, moves and turns ahead toward an extended line from a second straight service path which is another straight service path, moves straight back from an intersection with the extended line from the second straight service path until the work machine reaches an extended line from the first straight service path, and then moves and turns ahead toward an intersection between the second straight service path and the contour service path; the second turning behavior being for allowing the work machine to turn from one straight service path to another straight service path in such a manner that the work machine travels along the first straight service path, passes through the intersection between the first straight service path and the contour service path, moves ahead by a predetermined distance on the extended line from the first straight service path, moves and turns back toward the extended line from the second straight service path, moves straight ahead from the intersection with the extended line from the second straight service path until the work machine reaches the extended line from the first straight service path, and then turns back toward the extended line from the second straight service path; and the third turning behavior being for allowing the work machine to turn from one straight service path to another straight service path in such a manner that the work machine travels the first straight service path, passes through the intersection between the first straight service path and the contour service path, moves and turns ahead in the direction opposite to the second straight service path, stops temporarily, moves straight back to the intersection with the extended line from the first straight service path, and turns back toward the extended line from the second straight service path.

9. The work machine as claimed in claim 8 , wherein the controller records the contour service path, the straight service paths, and the bridge line path in a predetermined memory with these paths being associated with a map of the target area, and produces the travel control signal according to the current position and the information recorded on and read from the memory at the beginning of the operation in the target area, thereby allowing a self-propelled operation of the work machine.

10. A computer system mounted on a work machine, the computer system including a computer program for causing the computer to include a controller, that achieves a predetermined operation while moving a target area, the computer program being adapted to make the computer system function as: a detection unit configured to detect a behavior and a current position of the work machine; a service path defining unit configured to define a contour service path and a plurality of straight service paths, the contour service path running along the periphery of the target area, the straight service paths being defined by dividing the target area enclosed by the contour service path into two or more blocks with straight lines; a turning behavior defining unit configured to determine intersections between the contour service path and a pair of straight service paths, the pair of straight service paths being adjacent two of the straight service paths, the work machine being designed to travel along one of the pair of straight service paths in a first direction and travel along the other of the pair of straight service paths in a second direction that is opposite to the first direction, the turning behavior defining unit defining a turning behavior including backward movement of the work machine along a path connecting the adjacent intersections; and a control unit configured to produce a travel control signal to control a travel drive mechanism included in the work machine by using the travel control signal, the travel control signal being used to move the work machine along the contour service path and the straight service paths defined by the service path defining unit on anywhere other than the intersections between the contour service path and the straight service paths, based on the behavior and current position of the work machine traveling in the target area and information about their changes, and to turn the work machine in accordance with the turning behavior defined by the turning behavior defining unit when the work machine reaches one of the intersections, wherein the turning behavior defining unit is adapted to define at least one of first, second, and third turning behaviors, based on geographical features and attribute information including the body size of the work machine, a work width, and a shape of a curved line path followed by the work machine when it turns, the first turning behavior being for allowing the work machine to turn from one straight service path to another straight service path in such a manner that the work machine travels along a first straight service path that is one of the pair of straight service paths, passes through an intersection between the first straight service path and the contour service path, moves and turns ahead toward an extended line from a second straight service path which is another straight service path, moves straight back from an intersection with the extended line from the second straight service path until the work machine reaches an extended line from the first straight service path, and then moves and turns ahead toward an intersection between the second straight service path and the contour service path; the second turning behavior being for allowing the work machine to turn from one straight service path to another straight service path in such a manner that the work machine travels along the first straight service path, passes through the intersection between the first straight service path and the contour service path, moves ahead by a predetermined distance on the extended line from the first straight service path, moves and turns back toward the extended line from the second straight service path, moves straight ahead from the intersection with the extended line from the second straight service path until the work machine reaches the extended line from the first straight service path, and then turns back toward the extended line from the second straight service path; and the third turning behavior being for allowing the work machine to turn from one straight service path to another straight service path in such a manner that the work machine travels the first straight service path, passes through the intersection between the first straight service path and the contour service path, moves and turns ahead in the direction opposite to the second straight service path, stops temporarily, moves straight back to the intersection with the extended line from the first straight service path, and turns back toward the extended line from the second straight service path.

11. A work machine controller comprising: a detection unit configured to detect a behavior and a current position of a work machine that achieves a predetermined operation while moving a target area; a service path defining unit configured to define a contour service path and a plurality of straight service paths, the contour service path running along the periphery of the target area, the straight service paths being defined by dividing the target area enclosed by the contour service path into two or more blocks with straight lines; a turning behavior defining unit configured to determine intersections between the contour service path and a pair of straight service paths, the pair of straight service paths being adjacent two of the straight service paths, the work machine being designed to travel along one of the pair of straight service paths in a first direction and travel along the other of the pair of straight service paths in a second direction that is opposite to the first direction, the turning behavior defining unit defining a turning behavior including backward movement of the work machine along a path connecting the adjacent intersections; and a control unit configured to produce a travel control signal to control a travel drive mechanism included in the work machine by using the travel control signal, the travel control signal being used to move the work machine along the contour service path and the straight service paths defined by the service path defining unit on anywhere other than the intersections between the contour service path and the straight service paths, based on the behavior and current position of the work machine traveling in the target area and information about their changes, and to turn the work machine in accordance with the turning behavior defined by the turning behavior defining unit when the work machine reaches one of the intersections, wherein the service path defining unit defines a bridge line path to a destination point by defining, in addition to the contour service path and the straight service paths, a circle whose center is at a current stay position of the work machine and whose radius is equal to n (n is a natural number) times the length from the current stay position to a check position after the work machine has traveled a predetermined distance, selecting a position on the periphery of the circle that is closest to the destination point, the position corresponding to an intersection between the periphery of the circle and a line segment connecting the current stay position to the check position, redefining the circle with this position used as a new stay position, and repeating these operations until the new stay position gets close to the destination point.

12. A work machine that achieves a predetermined operation while moving a target area comprising a controller, the controller having: a detection unit configured to detect a behavior and a current position of the work machine; a service path defining unit configured to define a contour service path and a plurality of straight service paths, the contour service path running along the periphery of the target area, the straight service paths being defined by dividing the target area enclosed by the contour service path into two or more blocks with straight lines; a turning behavior defining unit configured to determine intersections between the contour service path and a pair of straight service paths, the pair of straight service paths being adjacent two of the straight service paths, the work machine being designed to travel along one of the pair of straight service paths in a first direction and travel along the other of the pair of straight service paths in a second direction that is opposite to the first direction, the turning behavior defining unit defining a turning behavior including backward movement of the work machine along a path connecting the adjacent intersections; and a control unit configured to produce a travel control signal for traveling along the contour service path and the straight service paths defined by the service path defining unit on anywhere other than the intersections between the contour service path and the straight service paths, based on the behavior and current position detected by the detection unit and information about their changes, and turning in accordance with the turning behavior defined by the turning behavior defining unit when the work machine reaches one of the intersections; the work machine further comprising a drive mechanism that is adapted to drive itself in response to the travel control signal produced from the controller, wherein the service path defining unit defines a bridge line path to a destination point by defining, in addition to the contour service path and the straight service paths, a circle whose center is at a current stay position of the work machine and whose radius is equal to n (n is a natural number) times the length from the current stay position to a check position after the work machine has traveled a predetermined distance, selecting a position on the periphery of the circle that is closest to the destination point, the position corresponding to an intersection between the periphery of the circle and a line segment connecting the current stay position to the check position, redefining the circle with this position used as a new stay position, and repeating these operations until the new stay position gets close to the destination point.

13. A computer system mounted on a work machine, the computer system including a computer program for causing the computer to include a controller, that achieves a predetermined operation while moving a target area, the computer program being adapted to make the computer system function as: a detection unit configured to detect a behavior and a current position of the work machine; a service path defining unit configured to define a contour service path and a plurality of straight service paths, the contour service path running along the periphery of the target area, the straight service paths being defined by dividing the target area enclosed by the contour service path into two or more blocks with straight lines; a turning behavior defining unit configured to determine intersections between the contour service path and a pair of straight service paths, the pair of straight service paths being adjacent two of the straight service paths, the work machine being designed to travel along one of the pair of straight service paths in a first direction and travel along the other of the pair of straight service paths in a second direction that is opposite to the first direction, the turning behavior defining unit defining a turning behavior including backward movement of the work machine along a path connecting the adjacent intersections; and a control unit configured to produce a travel control signal for traveling along the contour service path and the straight service paths defined by the service path defining unit on anywhere other than the intersections between the contour service path and the straight service paths, based on the behavior and current position detected by the detection unit and information about their changes, and turning in accordance with the turning behavior defined by the turning behavior defining unit when the work machine reaches one of the intersections; the work machine further comprising a drive mechanism that is adapted to drive itself in response to the travel control signal produced from the controller, wherein the service path defining unit defines a bridge line path to a destination point by defining, in addition to the contour service path and the straight service paths, a circle whose center is at a current stay position of the work machine and whose radius is equal to n (n is a natural number) times the length from the current stay position to a check position after the work machine has traveled a predetermined distance, selecting a position on the periphery of the circle that is closest to the destination point, the position corresponding to an intersection between the periphery of the circle and a line segment connecting the current stay position to the check position, redefining the circle with this position used as a new stay position, and repeating these operations until the new stay position gets close to the destination point.